Process of manufacturing aluminum alloy



Pairwise s2...- 1'4, 1926.

2mm nnn'rnzsnnm AND HENRY ma: moment, or mars, rnancn.

.rnocnss or man'urnc'runme nnumnum: ALLOY.

no mawm Application menrune 15,- 19:25,

The present invention has for its subject a new aluminum alloy of whichthe density is substantially equal to that of aluminum itself, but ofwhich. the mechanical strength is -much higher than that of aluminum.This alloy ,is essentially characterized by the fact that itscomposition includes copper, manganese, iron and silicon em form offerro-silicon, tungste magnesium, also cadmium, and aluminum, insuitable determined proportions ieldingi a metal which may be subjected0 any mechanical treatment ,(such asv rolling, drawing, hammering, wiredrawin and so forth, or even cast and which int is case gives productsfree from cracks and flaws.

The invention also relates to the process of manufacture of the saidalloy, according to which process there is first prepare a rich alloy ofthe body above specified by fusion in a plumbago crucible lined withmagnesia and containing a certain quantity of a mixture of woodcharcoal, calcium fluoride, oxide of magnesium and arsen'eous acid, therich alloy thus produced being after scouring, run into ingot moulds forsubse quent incorporation in aluminum in the proportion (variableaccording to the uses for which the metal is adapted) of 10 to 15 partsby weight of rich alloy to .90 to 85 parts by weight of aluminum. S

Einally the invention has for its object a modification of the process,which'modification is more particularly applicable in the case of alloysadapted to be fused, and in which the magnesium and cadmium (this latterbody may be replaced by sodium) are only inco' orated at the moment whenthe rich alloy is mixed with the aluminum, this inag'ne'sia and in thebottom of incorporation being made at a temperature at most equal to 725C.

With reference to examples which are given solely as examples of themethods of car ing the invention into effect, be 'escribed the method ofpreparation of alloys suitable for various uses. In all cases the richalloy is prepared by fusing the con stituents in a plumbago cruciblelined with i which there are; first placed 25 grammes of the following--.mixture:

" x Grammes.

-Pulverized' beech charcoal 1000 Naturalcalciumfluoridenur 1000yO'xidiofmagnesium; 250

Arseneous acid -=.1

loyed 1n the there will- 1 casting there are added,

Serial No. 37,573,.and in France May 11, 1925.

The crucible heated in a furnace permit- 7 ting of obtaining a regularand constant temperature (heavy'oil furnace or a furnace forheatvrecuperation ofthe Bigot system,

for example). When the fusion has been effected, the alloy time by meansof a; rod of carbon from a retort lined with magnesia (a. rod of ironshould never be used for this operation). Then from the surface of themass in fusion The composition of the rich alloy thus pre- 60 isagitated for a very long pared varies according to the use to which thefinal alloy is adapted to be applied. Example I .-For obtaining anadapted to form plates, rods, tubes, wires, sections and so forth, therich alloy is prepared from the following substances: copper, 40grammes; manganese, 2 grammes; ferro; silicon, 5.35 grammes, having 55%iron and silicon (ice. iron 3.95 gms.) tungsten, 2 grammes; magnesium,15 grammes; aluminum, 35.65 grammes. The quantity of rich alloy obtainedby fusing the preceding substances, in the manner indicated above, isincorporated in 900 grammes of pure aluminum (i. e. 99 to 99.5% pu're).

Example I I .,-The rich alloy for the preparation of a meal adapted tureof castings of any nature, is obtained by fusing: copper, 42 grammes;manganese, 2 grammes; ferro-silicon, 5.35 grammes, having iron andsilicon 45% gms. and silicon 2.40 gms); tungsten, 1 gramme; magnesium,20 grammes; aluminum, 9.65 grammes.

is incorporate in 900 grammes of pure aluminum. According to oneessential feature of the invention, in thisjcase particularly for thepreparation of an alloy adapted for a ing the rich alloy to thealuminum, 20 amines of cadmium, this addition being or the purpose ofeliminating cracks and flaws in the castings. y

The magnesium which enters into the formulae of the rich alloys whichhave been m- "dicated above (and also in the formula of the thirdexample hereinafter set forth) may be added to the other constituents[of the gms, silicon 2.40

tfthe time of add-- alloy 7 for the manufaca The vquantit of rich alloythus obtained 65 ,there is removed the mixture of powder and 1111111mass.

In all cases it is advisable, before adding these additions, to purifythe metal, as otherwise there is the risk that the magnesium is drawninto the slag. On the other hand it is essential to operate at atemperature which does not exceed 725 "C. The fusion of the purealuminum, with the incorporation of the appropriate rich alloy, ispreferably e'fi'ected in a plumbago crucible lined with magnesia andheated in an ordinary coke furnace.

The cadmium may be replaced by an equivalent quantity of sodium.

Example III.-A formula similar to the preceding is particularlysuit-able for the manufacture of engine pistons copper, 52.50

' grammes; manganese, 5 grammes: ferro silicon, 5.50 grammes, havingiron and silicon 45% (i. e. iron 3.03 gms, and silicon 2.47 gms.)tungsten, 1 gramme; magnesium, 20 grammes; aluminum, 46 grammes.

This quantity of ri'ch'alloy is incorporated in 850 grammes of purealuminum with the addition, under the conditions specified above, of 20grammes of cadmium. The 20 grammes of magnesium called for by theformula of the rich alloy may be added at the same moment as the.cadmium instead of being fused with the other constituents of the richalloy.

Irrespective. of the forinula adopted, it is important, in order toobtain products of good quality and constant characteristics. to

use only pure metals and start with cu pros in the preparation of therich alloys. The metal adapted to be rolled should be previously heatedfor one hour at a temperature between 400 and 450 C. After two or threerollings, the sheet should be re-heated under the same conditions, andthis treatment is repeated until the required thickness is obtained.The'sheet istthen annealed at 450 0., and then immersed in a bath of hotwater to which 5% of glycerine has been added. Annealing can then beeffected at atemperature of 450 to 475 O., and then the plate is allowedto cool slowly in air.

The manufacture of tubes, wires, rods, sections, is effected in the samemanner.

\ completed, it is advisable to'allow the metalto mature for from eightto ten days; and

subjecting them for one hour to annealing at a temperaure of 200 to 2500-, which annealing is followed by immersion in a bath of boilingywaterto which 5% of glycer- Once the mechanical treatment has been II andIII)' can'be promoted by ine has been added. The same result is obtainedby allowing -the 'furnace to cool after annealing for one hour.

The aluminum alloy in the form of castings obtained according to theinvention can be readily tempered.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is 1. A process for the manufacture of analuminum alloy comprising fusing in a plumbago crucible lined withmagnesia and containing a mixtureof wood charcoal, calcium fluoride,oxide of magnesium, and arseneous acid, a mixture of copper, manganese,ferro-silicon, tungsten, magnesium, and aluminum, so as' to roduce arich alloy,

,scouring the rich a1 0y, running the rich alloy into ingot moulds, andsubsequently mixing the rich alloy with pure aluminum.

2. A process for the manufacture of an al minum alloy comprising fusingin a plumbago crucible lined with magnesia and containing a mixture ofwood charcoal, cal cium fluoride, oxide of magnesium, 'and arseneousacid, a mixture of copper, manganese ferro-silicon. tun sten ma esiumand.

aluminum, so as to produce. a rich alloy, scouringthe rich alloy,running the rich alloy into ingot moulds, and subsequently mixing therich alloy with pure aluminum, in .the proportion of 10 to 15 parts byweight of-rich alloy to 90 to 85 parts by weight of aluminum. r

3. A process for the production of an aluminum alloy for the productionofcastings comprising fusing copper, manganese, ferro-silicon, tungsten,magnesium, and aluminum, in a plumbago crucible lined with magnesia andcontaining a mixture of wood charcoal, calcium fluoride, oxide ofmagnesium, and arseneous acid, the rich alloy thus obtained beingscoured, run into ingot moulds, and then mixed with aluminum and whilstmixing with the aluminum, adding magnesium and cadmium, this additionbeloy thus obtainedbeing scoured, run into ingot moulds, and then mixedwith aluminum, and whilst mixing with the aluminum, adding magnesium andsodium, this addition being made at' a temperature of about In witnesswhereof, we hereunto subscribe our riames this 3rd day of June, 1925.

- HENRY DE MONTBY. PIERRE BERTHELEMY

